CKM 2010, September 6 th -10 th, Warwick, UK Summary of WG I Prepared together with Albert Young and Federico Mescia Thanks to all the speakers and the organizers Tommaso Spadaro LNF INFN

e 1) Tree-level mediated decays -> CKM unitarity => High Precision SM tests  3) FCNC processes -> SUSY, Little Higgs …. D. Guadagnoli, P. Dimopoulos 2) Lepton Universality test --> sensitivity to the Higgs sector C. Lazzeroni GG G F V ud G F V us P. Debevic D. Melconian, I. Towner, B. Maerkerich, A. Juttner, W. Marciano A.Juttner, A. Ramos, R. Escribano, K. Maltman, M. Veltri, E. De Lucia, B. Sciascia +

GG See talk by P. Debevic: MuLAN collaboration G F = (7) x GeV -2 (0.6 ppm) avg:   = ± 2.2 ps (1.0 ppm) Final result after analysis of data sets Impact on G  : the normalization of the Flavor couplings New and final MuLan result for  lifetime

 lifetime measurements, 60 years of history 11 ppm 16 ppm

  : experiment and theory facing each other, QED radiative corrections, van Ritbergen & Stuart, Nucl. Phys. B564 (2000) 343, weak interaction loop corrections

GG G F V ud G F V us P. Debevic: MuLAN A.Juttner, A. Ramos, R. Escribano, K. Maltman, M. Veltri, E. De Lucia, B. Sciascia |V ud | 2 + |V us | 2 + |V ub | 2 = (6) Error budget: Vud Vus 2010: The Status of Lepton/Quark Universality 0.02% 0.5% D. Melconian, I. Towner, B. Maerkerich, A. Juttner, W. Marciano

V ud Nucleardecay: 0 + -> 0 + T=1 Neutron decay: n-> p l v Pion decay:   ->   l v Golden modes,  Both V and A contribute  only vector current (CVC)  small SU(2) corrections  A extracted by the  -asymmetry measurements (angular correlations) only vector current (CVC) but small Br (10 -8 ), experimental error still large and dominating Nuclear decay: mirror decays o Like n decay – V & A contribute, need angular correlations o Recent analysis provides quantitative extraction of V ud

Nucleardecay, 0 + -> 0 + transitions with T=1 1, the energy gap 2, the half life 3, the branching ratio I.I. Towner II.D. Melconian Vud determination involves 3 measurements: (Phase space)

Corrected Ft value See talk by D. Melconian

Ft values for 0 +  0 + transitions See talk by D. Melconian

Neutron decay: n-> p l v 2 experimental inputs

See talk by B. Märkisch Experimental status of n lifetime (PDG2010)

Status after new result from MAMBO II exp. See talk by B. Märkisch

Experimental status of = g A /g V after Perkeo II See talk by B. Märkisch

New See talk by I. S. Towner Current status of V ud

See talk by I. S. Towner Superallowed decay currently yields most precise value of V ud, limited by theory uncertainties: V ud = (22) V ud measurement very robust and stable along the years T = ½ mirror nuclei, neutron, and pion decay consistent but with larger errors Still a particularly vibrant and lively field: stay tuned

V us e   h s  l Only vector current (CVC): f + (0)=1 + (m s -m u ) 2 Small SU(2) br. corrections Only Axial current: no symmetry constraint f K /f 1 + (m s -m u ) f + (0), +0, c +0 ? (inclusive modes)  Both V and A but hard scale (m  ) + inclusiveness -> OPE

Vus extraction from Kl3

See talk by B. Sciascia (FlaviaNet Kaon WG), M. Veltri (Naxx), E. De Lucia The experimental players in a per-mil game

A critical re-analysis of literature data: BR’s,  ’s See talk by B. Sciascia (FlaviaNet Kaon WG)

Form Factor parameterization

See talk by B. Sciascia (FlaviaNet Kaon WG) Form Factors: dispersive approach

FF: new results coming, NA48/2 See talk by M. Veltri (NA48/NA62)

New results will come in a near future, KLOE-2 See talk by E. De Lucia (KLOE/KLOE-2)

New results will come in a near future, NA62 New Player are coming NA62 -> E. De Luci See talk by M. Veltri (NA48/NA62)

A new interesting idea to improve FF extraction See talk by R. Escribano

Promising: significant improvements for K  3

Present status of V us f+(0) from Kl3 data vs Theory still driving the error in the charged modes: SU(2) breaking corr.: See talk by B. Sciascia (FlaviaNet Kaon WG)

Present status of f+(0) from Lattice See talk by A. Jüttner (FlaviaNet Lattice WG) A precision of ~ 0.5% is possible

Present status of f+(0) from Lattice See talk by A. Jüttner (FlaviaNet Lattice WG) Averages:

Data can cross-check Lattice or vice-versa See talk by B. Sciascia (FlaviaNet Kaon WG)

A. Juttner

2 results with NF=2+1 Similar accuracy, both published: f K /f  = 1.192(7)(6)BMW 2010*Wilson f K /f  = 1.189(2)(7)HPQDC 2007Staggered f K /f  = 1.198(1)( )MILC 2009Staggered Share advisable features of good lattice calculations Continuum limit, finite volume effects, small pion mass * See talk by A. Ramos f K /f the lattice state-of-the-art

Thorough analysis of main source of errors: Continuum limit, a  0 Finite volume effects, L = Na wrt 1/m Small m , corrections as exp(-Lm), Lm required > 4 For each source, fit for different assumptions Simultaneous fit for all the systematic sources Error from the spread of the results f K /f  a systematic approach for error definition * See talk by A. Ramos

Close to the physical point! Simulated data close to the final value f K /f  BMW 2010: one of the 1500 fits See talk by A. Ramos a = fm a = fm a = fm

NP test: bounds on scalar component (H + ) See talk by B. Sciascia (FlaviaNet Kaon WG)

B. Marciano

An independent approach: Vus from decays Missing ->K4pi, K3pi.. Adding these modes Vus will raise See talk by K. Maltman (36) Comparison between lattice and other determinations

See talk by D. Guadagnoli

Standard approximation: Since K ~ -2MK, assume   = 45° Assume = 0 M 12 K = F(,) B K 8/3 F 2 K M 2 K B K from Lattice, known at 10% Evaluation of CKM constraint from  K up to 2007 See talk by D. Guadagnoli

Dramatic recent progress in B K evaluation (see P. Dimopoulos talk) Averages: Lahio, Lunghi, Van de Water: B K = 0.725(26) Lubicz:B K = 0.731(36) Present accuracy calls for improvements in  K CKM contraint * the Continuum Limit

Evaluation of superweak phase,   = 43.5° Buras, Guadagnoli (2008), Buras, Guadagnoli, Isidori (2010) re- esamine the  = 0 assumption and evaluate at NLO The net effect is k  = 0.94(2), imposing a ~2 tension, confirmed by UT fit and CKM fitter Evaluation of CKM constraint at present (2010) k  e isw /√2 See D. Guadagnoli talk

Important step forward by experiment for NP tests

RK in the SM

RK beyond the SM

The NA48/NA62 experiment

Measurement strategy: a counting experiment

Ke2 and Km2 Signal selection

Result for RK

RK: world average and Higgs exclusion plot

Summary of WG1 – The present status A general consideration: in the LHC era, still a lively and vibrant field The door to the flavor realm, G: New result by MuLan PSI: G now at the 1ppm level! Difficult to even think to improve on that Gm is like the fixed stars to which flavor physics has to confront Vud determination: An active community, many new experiments approved/running New experimental techniques, leading to new determination 0 +  0 + transitions dominate, but might change in a mid-term future Vus determination: rock solid status of experimental both from K l3 and K l2 major and fundamental improvements by Lattice News from K oscillation ( K )  2tension on CKM UT fits

Summary of WGI – The future perspectives Lattice reliability for Kaon observables gives confidence when going up to B (SuperB) Continuous further improvements from both experiments and theory on Kl3 FF’s are easily foreseen new results by KLOE, NAxx LFV NP test from Ke2/Km2 new presented for NA62 improvement on 1.3% mmt expected by KLOE And waiting for ultra rare K decay experiments: NA62, KOTO for NP in FCNC, K   (see WG III) CKM 1 st row unitarity and gauge universality represent a tight constraint for any NP model